Brian Welch operates the ITASE deep radar system during the group's traverse of East Antarctica to study environmental change.

Scientists traverse East Antarctica for ice cores

By Peter Rejcek, Antarctic Sun Editor

Posted January 28, 2007

Antarctic science requires many different methods in the pursuit of knowledge about the seventh continent and its place in the global ecosystem. The deeply browned face and ruddy cheeks of Paul Mayewski tell a story of scientists who understand the value of spending extended time in the environment they study.

“That’s very important,” said Mayewski, the director of the Climate Change Institute at the University of Maine. “It allows the scientists to develop, not just a scientific explanation, but an intuition about what the environment is like. That’s what we do: we’re interpreting the environment. If you don’t live in it, spend a lot of time in it, it’s very hard to do.”

Mayewski and colleagues from three other institutions completed a month-long overland traverse of a short stretch of East Antarctica in mid-January as part of the United States component of the International Trans Antarctic Scientific Expedition (ITASE). Twenty nations comprise ITASE, a cooperative effort to describe and understand Antarctic environmental change in a regional and global context over the last 200 to 1,000 years.

They can reconstruct the climate and atmospheric conditions by collecting samples and data through a variety of methods such as drilling ice cores to 100 meters, using ground-penetrating radar that peers to the bedrock underneath the ice sheets, and mapping the topography of the surface with high-precision GPS.

The program’s overarching goal is to develop a baseline of data about Antarctica’s climate to help interpret whether future changes around the continent are part of a natural pattern or anomalies caused by human influences as the global climate changes, according to Mayewski.

“Our goal, along with all the other ITASE countries, is to put together a reconstruction for climate in at least the last 200 years,” he explained, “… if not back to a thousand years, and use that to understand how the system operates and to determine whether the changes that are occurring now are unique.”

The timelines are not arbitrary. The 200-year timeframe encompasses a period when the human fingerprint from pollutants should begin to show itself in the chemistry of the ice cores. The relatively brief time period also lends itself to easier dating of the layers of the ice cores, which scientists read like tree rings. For example, researchers can identify sulfate concentrations from the major eruption of Indonesia’s Mount Tambora in 1815.

“This means we can calibrate our records back to that,” Mayewski said.

And in the last millennium, there have been documented natural climatic cycles of warmer and colder periods. The scientists want to characterize these natural variations to determine if future climate anomalies are analogous to the past or not.